EDIT: OP was edited to add another quote and a question, which gave me the clarification I needed.
It doesn't seem like tolerance is an issue here:
> And seven years later, it’s still working.
I still don't really get what your underlying point is.
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I'm curious why you shared this piece of the article? Are you attempting to say his fits of rage were due to cannabis withdrawals? I thought it was pretty clear from the article that this was the issue that was being treated.
Some clarification would be nice.
> At the time he was consumed by violent rages. He would bang his head, scream for hours and literally eat his shirts. At dinnertime, he threw his plates so forcefully that there was food stuck on the ceiling. He would punch and scratch himself and others, such that people would look at the red streaks on our bodies and ask us, gingerly, if we had cats.
But when I got the cookies right, he calmed down. His aggressions became less ferocious and less frequent. Mealtimes became less fraught. He was able to maintain enough self-composure that he even learned to ride a bike — despite every expert telling us it would never happen.
> Since he was an infant, I’d watched my son struggle. At 18 months, he underwent two major spinal-cord tumor surgeries, only weeks apart, and was immobilized in a cast for a year. After that, the violent rages began — sometimes as many as 300 in a day.